/*
  Write a program to sum the following series:

  1/3 + 3/5 + 5/7 + 7/9 + 9/11 + 11/13 + ... + 95/97 + 97/99
*/

public class E5_24 {
  public static void main(String[] args) {
    double sum = 0.0;
    for (int i = 1; i <= 97; i += 2) {
      sum += (double)i / (double)(i + 2);
    }

    System.out.println(sum);
  }
}
